London is blessed with a number of really first-rate shops selling antique maps.  Some have already been featured here on the blog – others most certainly will be in posts to come.  To visit any one of them is in some ways an even better experience than visiting one of the world’s great map libraries: many of the maps are manifestly of museum quality; there is no limit on how many maps you can ask to see and to handle, and there is expert guidance and a fund of professional knowledge on hand to be tapped into.  Best of all, you can actually buy them.

I made my way to the most recently established of these superlative map-shops just yesterday – Daniel Crouch Rare Books in Bury Street.  Just have a look at the crouchrarebooks.com website  to get the flavour.  I’ve been dealing in maps for over forty years.  I’m not easily impressed, but this is a seriously impressive shop.  The shelves lined with impossibly and improbably beautiful atlases.  Two of the ‘great’ maps of London hanging on the walls.  A gorgeous Richard Bennett map of London on an eighteenth-century fan. Several maps I knew of but had never, ever, seen before.  And not just maps and atlases, but other articles of delight – not just one, but two original waywisers – the pedometers used for measuring the roads by early mapmakers.

So many things to covet, and covet I do, but what I am really here for is to have a look at something very special – a theodolite which we believe once belonged to that great eighteenth-century mapmaker, Thomas Jefferys – the man primarily responsible for the surveying and re-mapping of large swathes of England in the 1760s.  Some years ago, I wrote the Oxford Dictionary of National Biography article on Jefferys and then followed that up with a longer and more detailed essay published in the now defunct journal Mapforum.  You can now read that, if you have a mind to, on a new parallel blog I’ve created as a home for my occasional formal essays and lectures – many of them previously unpublished or only published in not readily accessible journals.  There is a link under “Essays” at the top of the page.

Knowing my long-established interest in Jefferys, Daniel kindly invited me to have a look at the theodolite before it travels to its new home.  In a shop full of covetable things, how covetable is this?  Just as well it’s already sold.

Lacking its original tripod, but still a beautiful example of an eighteenth-century precision instrument.  Made by the London instrument-maker John Bennett of Soho (1708-1770) and featuring what was still quite a new development, the sighting telescope at the top, an innovation which transformed the utility of the theodolite and hence transformed the accuracy of mapmaking.  The first sighting telescope theodolite had been made in London while Bennett was still an apprentice.

John Bennett’s trade-card © British Museum – 1958,1006.2763

It is an object which would not be out of place in Moira Goff’s current Georgians Revealed exhibition at the British Library (something not to be missed).  An object fully worthy of a place there – quite extraordinary what treasures turn up in the London map trade.